help with 450r carb on 400ex

[jsmith2232]

I've done some reading on hooking up a 450 carb in my 416ex so i kinda have an idea of what i'm doing. with the setup in my sig what difference in jetting is there gonna be, I'm using a 170dj main, it runs great but is a little rich. also can I pull out my dynojet needle and adapter from my carb and put it in the 450's carb?

[atvracer980]

I would think so, your jetting should stay pretty close-maybe go down acouple sizes- its just a guessing game.

[jsmith2232]

Why would i have to go down if I am adding more air by putting a 4mm larger carb on? I would think that it would lean it out a bit and either be about right with the dj170 or maybe go up a size or two...